In the finishing of crank or cam shafts a number of different milling operations are used, the movements for the milling operations to be performed being made complex by the partially eccentric bearing or shaft pins. Ia system described for example in German 195 46 196 a workpiece, for example a crank shaft, is held with its ends in rotatably driven chucks such that it is rotatable about its central longitudinal axis. High-speed disk which are rotatable on a support are used for machining so that the workpiece can be followed.
In order to make a complete shape that is formed of a pair of undercut fillets and a machined pin, different cutting bodies are used to produce the undercut fillet and the cylindrical shape than are used for machining the pin of a crank-shaft bearing support. In order to make the undercut fillets the above-described cutting insert is used. The cutting inserts in question are secured by mounting screws in tool holders, and millers have cassettes with seats in which the cutting inserts are set and secured by a mounting screw.
Further uses of the above-described cutting inserts are in copy lathing.
With cutting inserts of the above-described type there are particular difficulties when an insufficient free angle is available for optimizing the radial and/or axial position. An increase in the free angle by minimizing the flank angle leads to overloading of the cutting edge. The likelihood of premature breakage of the cutting edge reduces the service life of the tool. The profile to be milled causes forces to be exerted in different directions on the cutting insert, making a stable mounting of the cutting insert in its seat difficult.